Number of 5-star hotels Amsterdam from 22 to 8

The number of 5-star hotels in Amsterdam has come down from 22 to 8.

The change is caused by the implementation of the new hotel classification system: the Benelux classification system has been replaced by the 'Nederlandse Hotel Classificatie'.
This was necessary to bring the hotel classification on an international level: the Netherlands used to have 22 5-star hotels, whereas the whole of the United States has only 32.

All hotels in Amsterdam will lose their current stars, and be judged again under the new system.
The Okura, l'Europe, the Amstel hotel and The Grand Hotel have already been judged and have maintained their 5 stars. The large Marriott hotel near the Leidseplein went from 5 to 3, and will fight the decision.

Apart from the 4 5-star hotels mentioned above, it is not clear what the remaining 4 5-star hotels in Amsterdam are. On websites such as bookings.nl (one of the largest booking websites in the Netherlands) and holland.com (the official website of the Netherlands Bureau of Tourism) list more than 8 5-star hotels in Amsterdam.
This may have to do with the transition from the old classification system to the new one, as this has not yet been finished.